Added slang shaders for compute nbody sample

shaders/slang/computenbody/particle_integrate.slang

@@ -0,0 +1,31 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+struct Particle
+{
+	float4 pos;
+	float4 vel;
+};
+// Binding 0 : Position storage buffer
+RWStructuredBuffer<Particle> particles;
+
+struct UBO
+{
+	float deltaT;
+	int particleCount;
+};
+ConstantBuffer<UBO> ubo;
+
+[shader("compute")]
+[numthreads(256, 1, 1)]
+void computeMain(uint3 GlobalInvocationID : SV_DispatchThreadID)
+{
+	int index = int(GlobalInvocationID.x);
+	float4 position = particles[index].pos;
+	float4 velocity = particles[index].vel;
+	position += ubo.deltaT * velocity;
+	particles[index].pos = position;
+}